Nonelectric squib assembly

ABSTRACT

A nonelectric squib assembly consisting of a squib body and a firing mechanism housing. The squib body includes a metallic seal separating a firing mechanism in the housing from a percussion primer in the squib body. The primary feature of the metallic seal is that it prevents missile motor pressure from producing a path for gases to flow back through the entire assembly. The metallic seal is dented by the firing mechanism to activate the primer thereby permitting primer gases to ignite a charge of boron-potassium nitrate carried in the squib body, which in turn is used to initiate the motor ignitor.

United States Patent [7 2] Inventor Rudolph E. Nett Los Angeles, Calif.[21] Appl. No. 823,351 [22] Filed May 9, 1969 [45] Patented Oct. 5, 1971[73] Assignee The United States of America as represented by theSecretary of the Army [54] NONELECTRIC SQUIB ASSEMBLY 1 Claim, 1 DrawingFig. I [52] US. Cl 102/29 [51] Int. Cl. F42c 15/06 [50] Field of Search102/27, 29, 45,497, 70, 86.5, DIG. 1

[56] References Cited UNITED STATES PATENTS 3,114,290 12/1963 Harvey etal 102/DlG. 1

3,129,663 4/1964 Schnepfe,.lr. 102/27 3,274,937 9/1966 Kyle l02/28XPrimary Examiner-Verlin R. Pendegrass Attorneys-William G. Gapcynski,Lawrence A. Neureither,

Leonard Flank and Charles R. Carter ABSTRACT: A nonelectric squibassembly consisting of a squib body and a firing mechanism housing. Thesquib body includes a metallic seal separating a firing mechanism in thehousing from a percussion primer in the squib body. The primary featureof the metallic seal is that it prevents missile motor pressure fromproducing a path for gases to flow back through the entire assembly. Themetallic seal is dented by the firing mechanism to activate the primerthereby permitting primer gases to ignite a charge of boron-potassiumnitrate carried in the squib body, which in turn is used to initiate themotor ignitor.

PATENTEU Gm 519?: 3,610,151

Rudolph E. Nefl INVENTOR NONELECTRIC SQUIB ASSEMBLY BACKGROUND OF THEINVENTION SUMMARY OF THE INVENTION The present invention provides asolution to this problem by providing a nonelectric squib which offersless hazard to operating personnel and property than the electric squibyet performs all the functions required of an electric squib. Thisperfon'nance is accomplished by a metallic seal that prevents missilemotor pressure from producing a path for gases of flow back through theentire assembly. The seal also allows the use of a small charge to drivea firing pin to dent the seal and thereby initiate the squib. Finalarming is performed external to the missile and late in the countdownthus reducing exposure of personnel to hazard.

This invention may be better understood from the following detaileddescription taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE shown in the drawingis a sectional perspective view of the nonelectric squib.

PREFERRED EMBODIMENT OF THE INVENTION Reference numeral 1 indicatesgenerally the nonelectric squib assembly. A firing mechanism housing 2is shown in axial alignment with and attached at one end of a squib bodyand houses a small booster charge (not shown). The firing mechanism issecured to the squib body to complete final anning of the missile. Ashear pin 3 holds a piston-type firing pin 4 until the booster chargeforces pin 4 thus shearing pin 3 and allowing pin 4 to slidably moveforward. The firing pin has an operating contact point 4: The squib bodyincludes a first chamber 6 housing a percussion primer 7. A seal 8 is ina thin disc made of metal, such as copper,'and is attached in a positionso that one side thereof is adjacent contact point 4 and the oppositeside of the seal closes off one end of chamber 6.

This seal does not rupture when dented by contact point 4 and thusprovides a hermetic seal for the squib body. The seal also preventsmissile motor pressure from producing a path for gases to flow backthrough the entire assembly. An inner disc 9 is made of aluminum foiland located at the opposite end of chamber 6 separating this chamberfrom one end of a second chamber 10. The primer in chamber 6, whenactivated, will emit gases that will rupture disc 9 and thereby enterchamber 10 which contains an igniter charge such as boron-potassiumnitrate (B-KNO identified by reference numeral II. A composite disc 12at the opposite end of chamber 10 is a combination made up of a micadisc 13 and a mild steel disc I4. After the igniter charge is ignited,composite disc 12 ruptures to allow the output of the igniter charge toinitiate the motor ignitor.

In operation a detonation wave is transmitted to the booster charge inthe firing mechanism housing, the charge ignites and drives the firingpin forward shearing the shear pin. The contact point of the firing pindents the metallic seal to activate the percussion primer. Alter theprimer has been activated the primer gases rupture the inner disc andthe gases are emitted into the chamber containing the igniter chargesuch as boronpotassium nitrate which in turn is ignited. The output ofthe igniter charge ruptures the composite disc and is then used toinitiate the motor igniter.

I claim:

1. A nonelectric squib assembly for igniting a missile motor and forpreventing gas flowback through the assembly comprising: a squib bodyhaving a firing mechanism housing at one end thereof, a first chamberand a second chamber; a filing pin mounted for slidable movement withinsaid squib body, said firing pin having a contact point on one endthereof; a shear pin connected between said squib body and said firingpin to restrain movement of said firing pin until squib operation isstarted; a metallic seal disposed between said contact point and one endof said first chamber for hennetically sealing the firing pin from gasesflowing back when the missile motor is ignited; a percussion primerdisposed in said first chamber adjacent said metallic seal; a rupturableinner disc of aluminum foil separating said first chamber from saidsecond chamber and sensitive to gaseous pressures from said primer; amissile motor igniter charge disposed in said second chamber; and acomposite disc consisting of mica and mild steel discs at the oppositeend of said second chamber for separation of said squib ignition fromthe missile motor, whereby missile motor pressure is prevented fromproducing a path for motor gases to flow back through the entire squibassembly.

1. A nonelectric squib assembly for igniting a missile motor and forpreventing gas flowback through the assembly comprising: a squib bodyhaving a firing mechanism housing at one end thereof, a first chamberand a second chamber; a firing pin mounted for slidable movement withinsaid squib body, said firing pin having a contact point on one endthereof; a shear pin connected between said squib body and said firingpin to restrain movement of said firing pin until squib operation isstarted; a metallic seal disposed between said contact point and one endof said first chamber for hermetically sealing the firing pin from gasesflowing back when the missile motor is ignited; a percussion primerdisposed in said first chamber adjacent said metallic seal; a rupturableinner disc of aluminum foil separating said first chamber from saidsecond chamber and sensitive to gaseous pressures from said primer; amissile motor igniter charge disposed in said second chamber; and acomposite disc consisting of mica and mild steel discs at the oppositeend of said second chamber for separation of said squib ignition fromthe missile motor, whereby missile motor pressure is prevented fromproducing a path for motor gases to flow back through the entire squibassembly.